An imaging device such as a CCD (charge coupled device) and a CMOS image sensor (complementary metal oxide semiconductor image sensor) includes a plurality of pixels that perform photoelectric conversion and a circuit unit that outputs an image signal in which the outputs of the individual pixels are aggregated. There are two types of imaging devices: a front-side illumination device in which both the pixel and the circuit unit are provided on one chip surface; and a back-side illumination device in which the circuit unit is provided on the front surface side and the pixel is provided on the back surface side. Of these, the back-side illumination device allows the density of pixels to be easily increased and has high sensitivity because the circuit unit is not provided on the light receiving surface. However, in the back-side illumination device, it is likely that color mixing between adjacent pixels (crosstalk) will occur. Hence, a high performance imaging device is required in which crosstalk between pixels is suppressed.